1. Field of the Invention
The present invention relates to a camera apparatus to be carried on a vehicle or to be installed for monitoring and, in particular, to such a camera apparatus which can be made small in size and is capable of having a wide angle of view.
2. Description of the Related Art
Conventionally, in order to secure the safe driving of a vehicle, the vehicle carries an onboard small-sized camera apparatus which can take a picture of a driver""s blind spot. This camera apparatus is installed, for example, in the rear portion of a large-sized vehicle in an exposed manner, while a picture taken by the camera apparatus can be displayed on a monitor disposed in front of a driver""s seat. Due to this, while confirming the condition behind the vehicle through the monitored picture, the driver is able to back up the vehicle.
Such a camera apparatus for monitoring is required to have a large angle of view, because it must take a picture of a wide area. In this case, however, there occurs a phenomenon in which the picture is distorted due to the wide angle of view. Also, in order to enhance the freedom of installation of the place of the camera apparatus, or, in order to prevent the camera apparatus from spoiling the design of the vehicle, a compact structure is required of such a camera apparatus. The angle of view of a camera lens, as shown in FIG. 12, includes a horizontal angle of view, a vertical angle of view, and a diagonal angle of view. These angles of view can be spread in a case where a wide-angle lens is used as the camera lens; and, due to the progress in the lens manufacturing technique, production of a wide-angle lens is now possible. In a case where the wide-angle lens is used as the camera lens, when compared with the horizontal and vertical angles of view, the diagonal angle of view is increased further, with the result that the distortion of the picture is increased.
On the other hand, the main body of the camera, as shown by dotted lines in FIG. 10(a), must be structured so as to have a size which is able to receive all of light rays is in a range of an angle of view (shown by solid lines in FIG. 10(a)) of the lens. However, as shown in FIG. 10(b), in a case where a part of the range of an angle of view of the lens cannot be received by the camera main body, as shown in FIG. 11, there occurs a so called vignetting phenomenon in which the corners of the monitor screen are cut off or out of focus.
To prevent such vignetting phenomenon, the camera main body must be made large in size according to an increase in the angle of view; however, this is contrary to the size reduction of the camera.
As described above, it is possible to make compact the camera lens and camera main body themselves but, in such a case, there occurs a vignetting phenomenon on the monitor screen, which blocks the size reduction of the camera apparatus.
The present invention aims at eliminating the drawbacks found in the above-mentioned conventional camera apparatus. Accordingly, it is an object of the invention to provide a camera apparatus which can be made compact in size and is capable of having a wide angle of view.
In attaining the above object, according to the invention, there is provided a camera apparatus including a camera main body and a convex mirror wherein a picture reflected by the convex mirror is taken by the camera main body.
According to the present camera apparatus, even if the angle of view of a camera lens is set small and the camera main body is structured compact, a picture corresponding to a wide angle of view can be taken through the convex mirror.